Embodiments relate well cementing operations and, more particularly, in certain embodiments, to use of solid surfactant composites in well cementing operations.
In well cementing operations, such as well construction and remedial cementing, cement compositions are commonly utilized. Cement compositions may be used in primary cementing operations whereby pipe strings, such as casing and liners, are cemented in wellbores. In a typical primary cementing operation, a cement composition may be pumped into an annulus between the exterior surface of the pipe string (e.g., casing, liner, etc.) disposed therein and the walls of the wellbore (or a larger conduit in the wellbore). The cement composition may set in the annular space, thereby forming an annular sheath of hardened, substantially impermeable material (i.e., a cement sheath) that may support and position the pipe string in the wellbore and may bond the exterior surface of the pipe string to the wellbore walls (or the larger conduit). Among other things, the cement sheath surrounding the pipe string should function to prevent the migration of fluids in the annulus, as well as protect the pipe string from corrosion. Cement compositions may also be used in remedial cementing methods, such as in squeeze cementing for sealing voids in a pipe string, cement sheath, gravel pack, subterranean formation, and the like.
Preparation of the wellbore for cementing operations may be important in achieving optimal zonal isolation. Conventionally, wellbores may be cleaned and prepared for the cement composition with a fluid train that precedes the cement composition and can include spacer fluids, flushes, water-based muds, and the like. Spacer fluids may be used in wellbore preparation for drilling fluid displacement before introduction of the cement composition. The spacer fluids may enhance solids removal while also separating the drilling fluid from a physically incompatible fluid, such as a cement composition. Spacer fluids may also be placed between different drilling fluids during drilling change outs or between a drilling fluid and completion brine. A liquid surfactant may be blended with the spacer fluid, for example, to allow the spacer fluid to be compatible with water- or oil-based drilling fluids. Inclusion of the liquid surfactant may enable the spacer fluid to achieve improved cleaning by removal of residual drilling fluid from the wellbore. For wellbores in which oil-based drilling fluids may have been used, the inclusion of liquids surfactants in the spacer fluids may serve the purpose of water-wetting surfaces in the wellbore, such as the wellbore wall and casing surfaces, resulting in better cement bonding. However, the use of liquid surfactants may be problematic. For example, liquid surfactants require the use of additional equipment on location to mix the spacer fluid and liquid surfactant properly, thus increasing the complexity of the well operation. Additionally, certain liquid surfactants may include one or more flammable components, thus increasing the expense associated with shipment, storage, and handling thereof.